Serine amide

An interesting application of A -sulfonyldiimidazole is illustrated by the synthesis of /f-lactams from substituted L-serine amides.[123]... 

Siam, K., V. J. Klimkowski, C. Van Alsenoy, J. D. Ewbank, andL. Schafer. 1987. Ab Initio Geometry Refinement of Some Selected Structures of the Model Dipeptide N-Acetyl N -Methyl Serine Amide. J. Mol. Struct. (Theochem) 152, 261-270. 

Fig. 7.13 Characteristic nonbonded interactions in N-acetyl N -methyl serine amide. Torsional angles to construct this figure were taken from K. Siam, S. Q. Kulp, J. D. Ewbank, and L. Schafer, J. Mol. Struct, 184 (1989) 143.

With the use of a family of three structurally related cyclic phosphoric acids (P-mix) as resolving agent, a diastereoisomerically pure salt containing the (25,5R)-enantiomer in 99% ee precipitates. The resolved t/ rc< -(4-methylthiophenyl)serine amide (Figure 7.5) can be used as an intermediate in the synthesis of thiamphenicol.22 Note that the individual phosphoric acids give salts of lower... 

FIGURE 7.5 Dutch Resolution of D,L-f/meo-(4-methylthiophenyl)serine amide with P-(-)-mix. 

Direct evidence of chiral monolayers came from fluorescence micrographs of -stearoylserine 4a with 6 as a fluorescent probe, which was not dissolved in the 2D crystals. Curved dendrites or small domains are formed, which are curved counterclockwise in L-serine amide monolayers (Figure 6.2d) and clockwise if the head group consists of / -serine (no Figure). 

Amino-acid analogs and uncommon L-amino acids W-acetyl-aspartate, W-acetyl-serine, oi-amino-n-butyrate, 3-aminoisobutyrate, aspartate ethyl or methyl ester, citrulline, cysteate, fumarate, glutathione, homoserine, erythro- and threo-p-hydroxyaspartate, isoasparagine, isoserine, malate, a- and p-methylaspartate, methylserine, phenol, serine amide, serine methyl ester, succinate [498, 747]... 

In a reaction generating -halo-amino carboxylic acid derivatives similar to the ones above, stirring a mixture of a serine amide and TMSCl in acetonitrile at reflux for 8 h furnishes the /8-chloro-amino amide in 72% yield (eq 53). Treatment with TMSI results in the same transformation, but provides only 20% yield of the desired iodide. 

A few antibiotics that are produced by Streptomyces spp. have structural affinities to single amino acids. Thus D-cycloserine (oxamycin), which has the structure XXVIII, could formally be obtained from D-serine amide by removal of the elements of water, or from D-alanine by an oxidative process. 

L-Serine amide L-Glutamic acid amide DL-a-Methylvaline amide ... 

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